Benralizumab in the Treatment of Eosinophilic Granulomatosis With Polyangiitis (EGPA) Study

This study is open-label which means that all subjects will receive the study medication. The medicine-benralizumab-will be given to subjects in addition to the medicines they are already taking to treat their EGPA such as oral steroids (e.g. prednisone) and medicines that reduce the activity of their immune system. Drugs that are sometimes used (i.e., standard of care) to reduce the activity of the immune system in EGPA (in addition to oral steroids) include azathioprine, methotrexate, mycophenolate mofetil and cyclophosphamide. Information about how the stud drug that you get affects the subjects body and their health will be collected through a number of tests, procedures and questions. The study medicine, benralizumab, will be given to subjects as one injection 30 mg under skin every four weeks for 12 weeks and then every 8 weeks for 16 weeks for a total of 5 treatments. During the treatment phase of this study, a study staff member will call the subjects to see how they are doing, what medications they are taking and if they are able to decrease their steroid use. The study is a total of 9 study visits in a 44 week time period. Everyone who takes part in the study will continue to receive his/her existing treatments for EGPA (although their dose of oral steroids may be reduced during the study.